Heretofore, a pipe joint described in Patent Literature 1 has been mentioned as a joining structure, which fits a thin-walled cylindrical member to a shaft member such as a solid shaft or a hollow shaft, crimps the thin-walled cylindrical member to then fix the thin-walled cylindrical member to the shaft member.
As shown in FIG. 14, in the pipe joint of Patent Literature 1, a connecting pipe 103 (thin-walled cylindrical member) is fitted to an outer circumference of a second pipe 102 (shaft member) fitted to an outer circumference of a first pipe 101. Then, a plurality of spots in an axial length direction of the connecting pipe 103 is crimped at crimped portions 104a and 104b. 
In the connecting pipe 103, a wall thereof is gradually thinned from one end thereof to other end thereof, and a crimp ratio of the crimped portion 104a on a thin-wall side is set smaller than a crimp ratio of the crimped portion 104b on a thick-wall side. As a result, the second pipe 102 is prevented from falling out by the crimped portion 104b having a larger crimp ratio. Meanwhile, cutoff of the second pipe 102, which is caused by a tensile stress, is prevented by the crimped portion 104a having a smaller crimp ratio.